Complete Guide for the Nikon D500

For 17 years, byThom has provided the best books on Nikon cameras, with the most detail and clarity you'll find. The #1 reader comment about Thom's books? "Thom should have written the Nikon manual [for that camera].”

Nikon Lens Contacts

An AF-S lens for the F-mount can have as many as ten contacts. Seven of these were defined back with the original Nikon autofocus system introduced with the Nikon N2020 (F501) camera in 1986.

Looking at the back of the lens and working counterclockwise:

VCC (power)

RW or H/S (read/write) (becomes RW1 if teleconverter is used)

LCLK (serial clock) (becomes LCLK1 if teleconverter is used)

LIO (serial data) (becomes LIO1 if teleconverter is used)

(teleconverter use) RW2

(AF-S use) LBAT

PGND (ground)

(AF-S use) PGND (ground)

(teleconverter use) LCLK2 (serial clock)

(teleconverter use) LIO2 (serial data)

The odd teleconverter extra (all the "2") signals allow the lens to talk simply through the teleconverter. The teleconverter only responds to the lens with a 1.25, 1.4, 1.6, 1.7, or 2x value, which the lens then processes and alters the focal length and aperture parameters in communicating with the camera on the main signals ("1" signals).